This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Doxorubicin prolongs survival and reduces tumor burden for many children and adults with cancer, but its use can cause irreversible congestive heart failure (CHF). Herceptin, Paclitaxel and Cyclophosphamide are also agents that are widely used for treatment of cancer and are associated with cardiotoxicity. Although a fall in left ventricular ejection (LVEF) detected during the course of chemotherapy may forecast the onset of CHF, it may occur only after irreversible cardiac damage has been sustained. Recently, cardiovascular magnetic resonance imaging (MRI) has been used to quantify regional changes in left ventricular diastolic regional relaxation. Studies in children have documented alterations in LV diastolic function in patients receiving Doxorubicin therapy often precede a deterioration in left ventricular ejection fraction. Pilot data generated from our institution indicates that MRI can be used to detect abnormalities of left ventricular relaxation in patients with varying degrees of LVEF. It is our intent to identify the association between cardiotoxicity and reductions in left ventricular diastolic relaxation or myocardial perfusion measured with MRI in cancer patients receiving chemotherapy.